Re: [XenPPC] [PATCH] Flush the ERAT early for secondary CPUs

[Segher Boessenkool <segher@xxxxxxxxxxxxxxxxxxx>]

>  p = probability of success = .997 (897 / 900)
>  q = probability of failure = .003 (1.0 - .997)
>  n = number of trials       = 2323
>  X = number of successes    = 2323
>
> Applying these to the binomial probability formula, we get:
>
>  P(2323) = 2323! / ((2323 - 2323)! * 2323!) * .997**2323 * .003** 
> (2323-2323)
>          = .0009307922
>
> So we conclude that the probability that our trials with this patch
> applied achieved exactly 2323 successes because of chance alone is . 
> 0009.
Not prematurely rounding p to a useless precision gives you

        p**2323 ~ 0.000428

even.  And that just calculates the chance that 2323 tries all
succeed given that the chance for one to succeed is 897/900; it
doesn't compare two hypotheses at all.


Segher


_______________________________________________
Xen-ppc-devel mailing list
Xen-ppc-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-ppc-devel